/* 
 * Copyright (c) 2009, Giora Kosoi
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Giora Kosoi ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Giora Kosoi BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#define BIN_BYTES_IN_ROW 4
#define BIN_BYTES_FROM_TEXT_WIDTH 4
#define BIN_OFFSET_WIDTH 10

#define BIN_PRINTED_LINE_LENGTH (BIN_OFFSET_WIDTH + \
                             BIN_BYTES_IN_ROW * 10 + \
                             BIN_BYTES_FROM_TEXT_WIDTH + 1)

//00000000: 00000000 00000000 00000000 00000000    ABCD 
//00000010: 00000000 00000000 00000000 00000000    ABCD 

static const char *BIN_BYTES[256] = 
{
    "00000000 ", "00000001 ", "00000010 ", "00000011 ", 
    "00000100 ", "00000101 ", "00000110 ", "00000111 ", 
    "00001000 ", "00001001 ", "00001010 ", "00001011 ", 
    "00001100 ", "00001101 ", "00001110 ", "00001111 ", 
    "00010000 ", "00010001 ", "00010010 ", "00010011 ", 
    "00010100 ", "00010101 ", "00010110 ", "00010111 ", 
    "00011000 ", "00011001 ", "00011010 ", "00011011 ", 
    "00011100 ", "00011101 ", "00011110 ", "00011111 ", 
    "00100000 ", "00100001 ", "00100010 ", "00100011 ", 
    "00100100 ", "00100101 ", "00100110 ", "00100111 ", 
    "00101000 ", "00101001 ", "00101010 ", "00101011 ", 
    "00101100 ", "00101101 ", "00101110 ", "00101111 ", 
    "00110000 ", "00110001 ", "00110010 ", "00110011 ", 
    "00110100 ", "00110101 ", "00110110 ", "00110111 ", 
    "00111000 ", "00111001 ", "00111010 ", "00111011 ", 
    "00111100 ", "00111101 ", "00111110 ", "00111111 ", 
    "01000000 ", "01000001 ", "01000010 ", "01000011 ", 
    "01000100 ", "01000101 ", "01000110 ", "01000111 ", 
    "01001000 ", "01001001 ", "01001010 ", "01001011 ", 
    "01001100 ", "01001101 ", "01001110 ", "01001111 ", 
    "01010000 ", "01010001 ", "01010010 ", "01010011 ", 
    "01010100 ", "01010101 ", "01010110 ", "01010111 ", 
    "01011000 ", "01011001 ", "01011010 ", "01011011 ", 
    "01011100 ", "01011101 ", "01011110 ", "01011111 ", 
    "01100000 ", "01100001 ", "01100010 ", "01100011 ", 
    "01100100 ", "01100101 ", "01100110 ", "01100111 ", 
    "01101000 ", "01101001 ", "01101010 ", "01101011 ", 
    "01101100 ", "01101101 ", "01101110 ", "01101111 ", 
    "01110000 ", "01110001 ", "01110010 ", "01110011 ", 
    "01110100 ", "01110101 ", "01110110 ", "01110111 ", 
    "01111000 ", "01111001 ", "01111010 ", "01111011 ", 
    "01111100 ", "01111101 ", "01111110 ", "01111111 ", 
    "10000000 ", "10000001 ", "10000010 ", "10000011 ", 
    "10000100 ", "10000101 ", "10000110 ", "10000111 ", 
    "10001000 ", "10001001 ", "10001010 ", "10001011 ", 
    "10001100 ", "10001101 ", "10001110 ", "10001111 ", 
    "10010000 ", "10010001 ", "10010010 ", "10010011 ", 
    "10010100 ", "10010101 ", "10010110 ", "10010111 ", 
    "10011000 ", "10011001 ", "10011010 ", "10011011 ", 
    "10011100 ", "10011101 ", "10011110 ", "10011111 ", 
    "10100000 ", "10100001 ", "10100010 ", "10100011 ", 
    "10100100 ", "10100101 ", "10100110 ", "10100111 ", 
    "10101000 ", "10101001 ", "10101010 ", "10101011 ", 
    "10101100 ", "10101101 ", "10101110 ", "10101111 ", 
    "10110000 ", "10110001 ", "10110010 ", "10110011 ", 
    "10110100 ", "10110101 ", "10110110 ", "10110111 ", 
    "10111000 ", "10111001 ", "10111010 ", "10111011 ", 
    "10111100 ", "10111101 ", "10111110 ", "10111111 ", 
    "11000000 ", "11000001 ", "11000010 ", "11000011 ", 
    "11000100 ", "11000101 ", "11000110 ", "11000111 ", 
    "11001000 ", "11001001 ", "11001010 ", "11001011 ", 
    "11001100 ", "11001101 ", "11001110 ", "11001111 ", 
    "11010000 ", "11010001 ", "11010010 ", "11010011 ", 
    "11010100 ", "11010101 ", "11010110 ", "11010111 ", 
    "11011000 ", "11011001 ", "11011010 ", "11011011 ", 
    "11011100 ", "11011101 ", "11011110 ", "11011111 ", 
    "11100000 ", "11100001 ", "11100010 ", "11100011 ", 
    "11100100 ", "11100101 ", "11100110 ", "11100111 ", 
    "11101000 ", "11101001 ", "11101010 ", "11101011 ", 
    "11101100 ", "11101101 ", "11101110 ", "11101111 ", 
    "11110000 ", "11110001 ", "11110010 ", "11110011 ", 
    "11110100 ", "11110101 ", "11110110 ", "11110111 ", 
    "11111000 ", "11111001 ", "11111010 ", "11111011 ", 
    "11111100 ", "11111101 ", "11111110 ", "11111111 ", 
};

static int l_bindump(lua_State *l)
{
    size_t len = 0;
    const unsigned char *input = get_substring(l, &len, 1, 2, 3);

    luaL_Buffer b; 
    luaL_buffinit(l, &b);

    size_t i = 0;
    while(i < len)
    {
        unsigned char *result = (unsigned char *)luaL_prepbuffer(&b);
        memset(result, 'X', LUAL_BUFFERSIZE);
        size_t column = 0;
        while(i < len && column < LUAL_BUFFERSIZE - BIN_PRINTED_LINE_LENGTH)
        {
            size_t line_start = i;
            sprintf((char *)(result + column), "%08x: ", line_start);
            column += BIN_OFFSET_WIDTH;
            size_t k = 0;
            while(k < BIN_BYTES_IN_ROW && i < len)
            {
                memcpy(result + column, BIN_BYTES[input[i]], 9);
                column += 9;
                ++i; ++k;
            }
            size_t space_length = BIN_BYTES_FROM_TEXT_WIDTH;
            if(k != BIN_BYTES_IN_ROW)
            {
                space_length += (BIN_BYTES_IN_ROW - k) * 9;
            }
            memset(result + column, ' ', space_length);
            column += space_length;
            k = 0;
            while(line_start + k < len && k < BIN_BYTES_IN_ROW)
            {
                unsigned char ch = input[line_start + k];
	            result[column] = isprint(ch) ? ch : '.';
                ++k; ++column;
            }
            result[column] = '\n';
            ++column;
        }
        luaL_addsize(&b, column);
    }
    luaL_pushresult(&b);
    return 1;
}

static int l_binstream(lua_State *l)
{
    size_t len = 0;
    const unsigned char *input = get_substring(l, &len, 1, 2, 3);

    luaL_Buffer b; 
    luaL_buffinit(l, &b);

    size_t i = 0;
    while(i < len)
    {
        unsigned char *result = (unsigned char *)luaL_prepbuffer(&b);
        size_t column = 0;
        while(i < len && column < LUAL_BUFFERSIZE - 8)
        {
            memcpy(result + column, BIN_BYTES[input[i]], 8);
            column += 8;
            ++i;
        }
        luaL_addsize(&b, column);
    }
    luaL_pushresult(&b);
    return 1;
}

static int l_frombinstream(lua_State *l)
{
    size_t len = 0;
    const unsigned char *input = get_substring(l, &len, 1, 2, 3);

    luaL_Buffer b; 
    luaL_buffinit(l, &b);

    if(len % 8 != 0)
    {
        luaL_error(l, "wrong format: input must be binstream with number of digits divisible by 8");
    }

    size_t i = 0;
    while(i < len)
    {
        unsigned char *result = (unsigned char *)luaL_prepbuffer(&b);
        unsigned char *current_byte = result;
        unsigned char *result_end = result + LUAL_BUFFERSIZE;
        while(i < len && current_byte < result_end)
        {
            char byte[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
            char *endptr = NULL;
            memcpy(byte, input + i, 8); 
            *current_byte = (unsigned char)strtol(byte, &endptr, 2);
            if(*endptr != '\0')
            {
                luaL_error(l, "wrong format: %s are not binary digits", byte);
            }
            ++current_byte;
            i += 8;
        }
        luaL_addsize(&b, current_byte - result);
    }
    luaL_pushresult(&b);
    return 1;
}

